Cardiac arrhythmias, such as ventricular fibrillation and ventricular tachycardia, can lead to sudden death, i.e., within minutes. Potentially lethal cardiac arrhythmias occur typically in patients experiencing a myocardial infarction or other conditions that cause ischemia in cardiac tissue. The high incidence of recurrent ventricular fibrillation and resulting sudden death indicates a need for effective treatment methods to prevent life-threatening arrhythmias.